Loaded and unloaded ring-oscillator circuits with an
electrical and surface-normal 850 nm optical readout are fabricated using a hybrid 0.8 mu
m silicon-CMOS/GaAs-AlGaAs MQW process. Measurements of the oscillation frequency of these
circuits show total capacitance associated with the flip-chip-bonded optical MQW
modulators as low as 52 fF